It is known that, in the approach phase that has to lead to the landing of an aircraft on a runway, the piloting of that aircraft is particularly difficult. In this approach phase, the pilot has a large amount of information, some of which allows him to avoid a contact between the tail or a wing and the ground, a hard landing or a leaving of the runway. Among this information there is principally the speed of the aircraft, the slope of the aircraft and the height of the aircraft with respect to the ground, these three pieces of information being displayed in the cockpit, such that the pilot can monitor them easily. Moreover, the view of the environment provides the pilot with a perception of his approach plan.
The total energy level of the aircraft, combining its speed and its height, is an essential parameter for estimating the risk of leaving the runway. However, it cannot always be estimated by the pilot. Moreover, the energy level can be altered by the wind.